Signatures of Chiral Superconductivity in Rhombohedral Graphene
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866912466956451840 |
|---|---|
| author | Han, Tonghang Lu, Zhengguang Hadjri, Zach Shi, Lihan Wu, Zhenghan Xu, Wei Yao, Yuxuan Cotten, Armel A. Sedeh, Omid Sharifi Weldeyesus, Henok Yang, Jixiang Seo, Junseok Ye, Shenyong Zhou, Muyang Liu, Haoyang Shi, Gang Hua, Zhenqi Watanabe, Kenji Taniguchi, Takashi Xiong, Peng Zumbühl, Dominik M. Fu, Liang Ju, Long |
| author_facet | Han, Tonghang Lu, Zhengguang Hadjri, Zach Shi, Lihan Wu, Zhenghan Xu, Wei Yao, Yuxuan Cotten, Armel A. Sedeh, Omid Sharifi Weldeyesus, Henok Yang, Jixiang Seo, Junseok Ye, Shenyong Zhou, Muyang Liu, Haoyang Shi, Gang Hua, Zhenqi Watanabe, Kenji Taniguchi, Takashi Xiong, Peng Zumbühl, Dominik M. Fu, Liang Ju, Long |
| contents | Chiral superconductors are unconventional superconducting states that break time reversal symmetry spontaneously and typically feature Cooper pairing at non-zero angular momentum. Such states may host Majorana fermions and provide an important platform for topological physics research and fault-tolerant quantum computing. Despite intensive search and prolonged studies of several candidate systems, chiral superconductivity has remained elusive so far. Here we report the discovery of robust unconventional superconductivity in rhombohedral tetra- and penta-layer graphene in the absence of moiré superlattice effects. We observed two superconducting states in the gate-induced flat conduction bands with Tc up to 300 mK and charge density ne as low as 2.4*1011 cm-2 in three tetralayer and two pentalayer devices. Spontaneous time-reversal-symmetry-breaking (TRSB) due to electron's orbital motion is found, and several observations indicate the chiral nature of these superconducting states, including: 1. In the superconducting state, Rxx shows magnetic hysteresis in varying out-of-plane magnetic field B, which is absent from all other superconductors; 2. the superconducting states are immune to in-plane magnetic field and are developed within a spin- and valley-polarized quarter-metal phase; 3. the normal states show anomalous Hall signals at zero magnetic field and magnetic hysteresis. We also observed a critical B of up to 1.4 Tesla, higher than any graphene superconductivity reported so far and indicates a strong-coupling superconductivity close to the BCS-BEC crossover. Our observations establish a pure carbon material for the study of topological superconductivity, and pave the way to explore Majorana modes and topological quantum computing. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2408_15233 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Signatures of Chiral Superconductivity in Rhombohedral Graphene Han, Tonghang Lu, Zhengguang Hadjri, Zach Shi, Lihan Wu, Zhenghan Xu, Wei Yao, Yuxuan Cotten, Armel A. Sedeh, Omid Sharifi Weldeyesus, Henok Yang, Jixiang Seo, Junseok Ye, Shenyong Zhou, Muyang Liu, Haoyang Shi, Gang Hua, Zhenqi Watanabe, Kenji Taniguchi, Takashi Xiong, Peng Zumbühl, Dominik M. Fu, Liang Ju, Long Mesoscale and Nanoscale Physics Chiral superconductors are unconventional superconducting states that break time reversal symmetry spontaneously and typically feature Cooper pairing at non-zero angular momentum. Such states may host Majorana fermions and provide an important platform for topological physics research and fault-tolerant quantum computing. Despite intensive search and prolonged studies of several candidate systems, chiral superconductivity has remained elusive so far. Here we report the discovery of robust unconventional superconductivity in rhombohedral tetra- and penta-layer graphene in the absence of moiré superlattice effects. We observed two superconducting states in the gate-induced flat conduction bands with Tc up to 300 mK and charge density ne as low as 2.4*1011 cm-2 in three tetralayer and two pentalayer devices. Spontaneous time-reversal-symmetry-breaking (TRSB) due to electron's orbital motion is found, and several observations indicate the chiral nature of these superconducting states, including: 1. In the superconducting state, Rxx shows magnetic hysteresis in varying out-of-plane magnetic field B, which is absent from all other superconductors; 2. the superconducting states are immune to in-plane magnetic field and are developed within a spin- and valley-polarized quarter-metal phase; 3. the normal states show anomalous Hall signals at zero magnetic field and magnetic hysteresis. We also observed a critical B of up to 1.4 Tesla, higher than any graphene superconductivity reported so far and indicates a strong-coupling superconductivity close to the BCS-BEC crossover. Our observations establish a pure carbon material for the study of topological superconductivity, and pave the way to explore Majorana modes and topological quantum computing. |
| title | Signatures of Chiral Superconductivity in Rhombohedral Graphene |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2408.15233 |